1. Field of the Invention
The present invention relates to a system for dicing a CSP plate into pellets and for transporting and putting them into a transport tray, and more particularly a CSP plate holder to be used therein.
2. Related Arts
Referring to FIG. 15, a CSP (abbreviated for xe2x80x9cChip Size Packagexe2x80x9d) plate 200 is composed of a plurality of semiconductor chips hermetically sealed and packaged with glass or epoxy resin as a whole. The CSP plate chip can be cut crosswise along the crossing lines 201 and 202 into individual CSPs of same size as a semiconductor. These CSPs are transferred to a transport tray for shipping, or they are transported to an assembling line in the factory to be built in printed circuit boards. Thus, small-sized electronic devices such as notebook-sized personal computers, cellular phones and such like can be provided.
A CSP plate 200 can be diced crosswise to individual pellets by using a dicing machine. Referring to FIG. 16, each CSP plate 200 is fixedly held to a frame F with the aid of adhesive tape T, and the CSP plate thus held can be diced as it is.
A plurality of CSP plate-and-frame combinations are laid on each other to form a stack, and the stack is put in a cassette. After the CSP plate has been diced, the diced CSP plate is still held on the frame, and the diced CSP plate-and-frame combination is put in the cassette. All CSP plates are cut into individual pellets, and then they are transported to the pick-up station where pellets are picked up from a selected diced CSP plate for transferring and putting one by one in a selected transport tray. The transport tray thus loaded with pellets are shipped or brought to an assembling line in the factory.
Apart from the dicing work, it is necessary that CSP plates 200 are fixedly held to frames F with the aid of adhesive tapes T. Before completing this, the dicing work cannot start, and accordingly the productivity is lowered. Also, extra apparatus need to be provided for applying tapes T both to frames F and CSP plates 200, and installation of such extra apparatus is disadvantageous from the economical point of view.
After picking up pellets from diced CSP plate-and-frame combinations, it is necessary that: used adhesive tapes T are peeled off from the frames F; new adhesive tapes T are applied to the frames F; and finally new CSP plates 200 are put on the tapes T. Specifically used frames F are collected to peel their adhesive tapes off, and new adhesive tapes are applied both to the frames F and the CSP plates 200. This work must be begun after finishing the pick-up work, and must be finished before resuming the dicing work. This is a cause for preventing the productivity from being improved. In addition, lots of used adhesive tape must be thrown away, causing a significant pollution in the surrounding.
What is aimed at by the present invention is to dice a CSP plate into pellets at an increased efficiency without causing any pollution in the surrounding.
To attain this object according to the present invention, a CSP plate holder for use in dicing a CSP plate into individual pellets and in transporting and putting them in a transport tray comprises: a flat plate for bearing a CSP plate thereon, said flat plate having a plurality of pellet areas each allotted to each of the individual pellets, each pellet area having a through hole made therein for sucking and fixedly holding the pellet, said flat plate having engagement means for holding said CSP plate while being transported.
The CSP plate holder can be used repeatedly, not producing any disposables which may cause pollution in the surrounding. Collection of used tapes and application of new tapes both to CSP plates and associated frames are not required, and accordingly the productivity can be improved.
The engagement means may comprise at least one suction hole made adjacent to the through hole in each pellet area for sucking and fixedly holding the pellet while the CSP plate is transported, and duct passages permitting the suction hole to communicate with a suction source for applying negative pressure to the pellet.
With this arrangement the CSP plate can be fixedly held by applying negative pressure to the CSP plate via the through holes while being diced, and by applying negative pressure to the diced CSP plate via the suction holes while being transported.
The flat plate may have at least one minute through hole made in each pellet area, thereby permitting the minute through hole to be selectively used in picking up the pellet for transporting to the transport tray. With this arrangement the pick up of each pellet is facilitated.
The CSP plate holder may comprise further an elastomeric sheet laid on said flat plate. Use of such an elastomeric sheet assures that a CSP plate be held in stable condition even though the CSP plate is somewhat bent. The elastomeric sheet may be of a synthetic resin.
The elastomeric sheet may be applied to the flat plate by an adhesive agent, which is sensitive to ultraviolet rays for reducing its adhesive power. Thus, removal of the elastomeric sheet is facilitated.
Other objects and advantages of the present invention will be understood from a CSP plate holder and a table for bearing the same according to preferred embodiments of the present invention, which are shown in accompanying drawings.